In this dissertation, I have verified that the striking purple color of the intermetallic compound AuAl₂, also known as purple gold, originates from surface plasmons (SPs). This contrasts to a previous assumption that this color is due to an interband absorption transition. The existence of SPs was demonstrated by launching them in thin AuAl2 films in the Kretschmann configuration, which enables us to measure the SP dispersion relation. I observed that the SP energy in thin films of purple gold is around 2.1 eV, comparable to previous work on the dielectric function of this material. Furthermore, SP sensing using AuAl₂ also shows the ability to measure the change in the refractive index of standard sucrose solution. AuAl₂ in nanoparticle form is also discussed in terms of plasmonic applications, where Mie scattering theory predicts that the particle bears nearly uniform absorption over the entire visible spectrum with an order magnitude higher than a lightabsorbing carbonaceous particle. The second topic of this dissertation focuses on plasmon enhanced fluorescence in gold nanoparticles (Au NPs). Here, I investigated the distance-dependent fluorescence emission of rhodamine green 110 fluorophores from Au NPs with tunable spacers. These spacers consist of polyelectrolyte multilayers (PEMs) consisting of poly(allylamine hydrochloride) and poly(styrene sulfonate) assembled at pH 8.4. The distance between Au NPs and fluorophores was varied by changing the ambient pH from 3 to 10 and back, which causes the swelling and deswelling of PEM spacer. Maximum fluorescence intensity with 4.0-fold enhancement was observed with 7-layer coated Au NPs at ambient pH 10 referenced to pH 3. The last topic of this dissertation examines a novel approach to assemble nanoparticles, in particular, dimers of gold nanospheres (NSs). 16 nm and 60 nm diameter NSs were connected using photocleavable molecules as linkers. I showed that the orientation of the dimers can be controlled with the polarization of UV illumination that cleaves the linkers, making dipolar patches. This type of assembly provides a simple method with potential applications in multiple contexts, such as biomedicine and nanorobotics. / PHD / This dissertation covers three related topics. The first is an investigation of the optical properties of the unusually colored purple gold, which is a blend of gold and aluminum with the chemical formula is AuAl₂. This compound is interesting in that the origin of this color is different from most other metals. In the case of gold, for example, the metal gold is yellow color by absorbing the blue component from white light, leaving behind yellow color reflected light. The blue light is absorbed by electrons that change their state from a lower energy to a higher one. In purple gold, the color results from a different phenomenon known as “surface plasmons.” Surface plasmons are waves consisting of many electrons that move back and forth near an interface between a metal and an electrical insulator. The energy of surface plasmons in purple gold is low and corresponds to the purple color in this compound. Recently, published theoretical work supports the possibility of surface plasmons in purple gold. In this dissertation, I experimentally verify the presence of surface plasmons in purple gold. To launch surface plasmons, light was reflected off of a purple gold film deposited on the hypotenuse of a prism with varying angles of incidence. Surface plasmons can be observed by the sudden dimming of reflected light. From this, I was able to extract the surface plasmon dispersion relation, which is the relation between the inverse of the wavelength and the energy of the surface plasmons. In addition, I computed the light absorption properties of purple v gold when it is used in a nanoparticle form. The computational result showed that small purple gold nanoparticles absorb light very well, which may be useful in photothermal cancer therapy and solar steam generation. The second dissertation topic comprises a study of fluorescent molecules. These are compounds that reemit light with a different and redder color than the color of the light that illuminates them. In this experiment, green fluorescent molecules were placed near the surface of gold nanoparticles to observe how the brightness of the light emission is affected by the distance between the molecule and the metal. The underlying mechanism is based on localized surface plasmon resonances in gold nanoparticles. Localized surface plasmon resonances are waves consisting of many electrons that oscillate inside the particle, and they only occur when light at certain frequency illuminate the particle. On the resonance, the particle also exhibits the brighter light around the particle’s surface but the dimmer light away from the particle’s surface. The light enhancement from the particle can change the light emission of the fluorescent molecules. If the fluorescent molecules were placed in the range of localized surface plasmon resonances, the light emission is increased owing to the brighter light from the particle. However, if the fluorescent molecules were placed further away from the range of localized surface plasmon resonances, the light emission is decreased owing to the dimmer light from the particle. The distance between the surface of gold nanoparticle and the fluorescent molecules was varied by wrapping the gold particles with ultra-thin films of different plastic polymers before attaching fluorescent molecules to the surface of the films. These polymer films have the property that they swell and shrink when the acidity and basicity of the solution of gold particles changes, which allows me to vary the distance between the gold particles and fluorescent molecules. The results showed that the observed light gets dimmer when the solution is more acidic. On the other hand, the brighter light is noticed when the solution is more basic, and this observation is repeatable many times. Moreover, my work differs from other published works vi in that the particles with the polymer films are more robust and stable than the other particles. This allows more design flexibility and suggests applications in biomedical or environmental research where the particles can be used to locally measure properties, such as acidity in confined spacers such as living cells. It may be possible to use this technique for tumor cells in our body or toxic pollutants in the air or water. The last dissertation topic involves assembling nanoparticles to build them into larger structures. In this experiment, I fabricated particle dimers that consisted of two gold nanospheres of different sizes. They were attached together by using small molecules that are sensitive to ultraviolet (UV) light, where these molecules allow small gold nanospheres to be attached to large gold nanospheres only in those locations on the large nanospheres that have been illuminated with a sufficient amount of UV light. To achieve this alignment, UV light with a linear polarization (a specific electric field direction) was used to select the area on the large nanospheres where the UV light was particularly intense and therefore able to break the molecules, leaving positively charged surface patches on the spheres. This results in the electrostatic attraction between the positive patches on the large gold nanospheres and the negatively charged small gold nanospheres. With this method, I was able to make dimers of nanospheres in a preferred alignment by changing the polarization of UV light. The experimental results showed a good yield of dipolar patches, which allows multifunctional nanostructures with applications in nanomedicine, optical sensing, nanoelectronics, etc.

Negli ultimi anni, la gestione illegale dei rifiuti ha attirato l’attenzione pubblica e dell’accademia. A causa delle sue conseguenze negative non solo per l’ambiente, ma anche per la salute pubblica e la crescita economica, gli esperti hanno cominciato ad esplorare le dinamiche del fenomeno e le possibilità di prevenzione. Alcuni studi hanno evidenziato l’esistenza di diversi fattori che possono determinare la gestione illegale dei rifiuti, ma pochi di essi hanno empiricamente testato la validità dei fattori stessi. Di conseguenza, si avverte la necessità di produrre nuova conoscenza sull’argomento. Il presente studio consiste in un’analisi esplorativa di fattori socio-economici, fattori di policy e di performance, e fattori criminali che influenzano la gestione illegale dei rifiuti in Italia. Dopo aver identificato le determinanti considerate rilevanti dalla letteratura, l’obiettivo è quello di testarle empiricamente. Per prima cosa, grazie all’unicità di un dataset creato sul contesto italiano, nello studio si indaga quantitativamente l’effetto di diversi fattori sul fenomeno attraverso un’analisi econometrica. Successivamente, lo studio prosegue con un’analisi “crime script” al fine di esplorare quali fattori suggeriti dalla letteratura e testati nella parte quantitativa emergono anche da casi studio e come effettivamente intervengono nel ciclo dei rifiuti italiano. I risultati indicano che la gestione illegale dei rifiuti è determinata da: i) uno scarso sviluppo economico e demografico, un alto livello d’istruzione nel territorio, la presenza di turisti; ii) l'inefficienza della normativa ambientale, delle forze dell’ordine e delle prestazioni sui rifiuti; iii) la presenza di criminalità organizzata e la diffusione di crimini economici e fiscali. Prendendo spunto da questi risultati, lo studio non solo aumenta la conoscenza sul fenomeno, ma è anche in grado di avanzare alcuni suggerimenti di policy per contrastare efficacemente le condotte illegali legate alla gestione dei rifiuti. / In the last several decades, illegal waste management (IWM) has attracted great academic and public attention. Due to its negative consequences not only for the environment, but also for public health and economic growth, scholars started to be interested in the dynamics of IWM and in how to prevent it. Some studies stressed the existence of different factors that can determine the phenomenon, but very few of them have empirically tested their validity. Consequently, developing new research on the topic is still necessary. The present study conducts an explorative analysis of the socio-economic, policy and performance-driven and criminal factors influencing IWM in Italy. After the identification of the most relevant determinants according to the literature, the objective is to empirically test them. First, thanks to a unique dataset focused on the Italian context, the study quantitatively investigates the effect of different factors on the phenomenon through an econometric analysis. Second, the study realises a crime script analysis to explore which factors suggested by the literature and tested in the quantitative part emerge also in concrete case studies and how they effectively intervene in the Italian waste cycle. Results indicate that IWM is determined by: i) a low level of economic development and population density, a high level of education and tourists’ presence; ii) inefficiency in environmental regulation, enforcement and waste performances; iii) the presence of organised crime and the diffusion of economic and fiscal crimes. According to these findings, the study not only deepens the knowledge of the phenomenon, but it is also able to provide some policy suggestions to efficiently hinder illegal conducts related to waste management.

Il Bilancio Partecipativo (BP) è probabilmente l’esempio più famoso ed interessante di governance locale per i suoi effetti democratici e redistributivi. Per via del coinvolgimento diretto dei cittadini nel processo decisionale, il BP è considerato una forma di democrazia diretta capace di ovviare agli attuali limiti della democrazia rappresentativa moderna. Tuttavia, ad un’attenta analisi, è possibile identificare nel suo funzionamento anche degli elementi rappresentativi che non sono mai stati presi molto in seria considerazione. Infatti, poiché la partecipazione avviene solitamente attraverso gruppi ed associazioni, nuove forme di rappresentanza e nuovi rappresentanti emergono in competizione con quelli tradizionali politici in termini di consenso, sostegno popolare e dunque legittimità. Il presente lavoro vuole andare oltre il pensiero corrente e proporre un’interpretazione originale del modello istituzionale del BP come una forma nuova ed alternativa di democrazia rappresentativa, in cui le organizzazioni della società civile assumono un ruolo centrale: dietro al BP vi sarebbe una sorta di democrazia ‘civile’. Questo punto di vista alternativo non solo può stimolare un ulteriore dibattito in letteratura, ma aprire anche degli scenari interessanti in relazione ai temi più generali della crisi delle istituzioni liberal-democratiche e del ruolo e dell’identità della società civile. / Participatory Budgeting (PB) is probably the most famous and interesting example of innovative local governance for its redistributive and democratic effects. Due to the direct involvement of citizens in the decision-making process, PB is celebrated as an example of direct democracy which can help to deal with the limits of representative democracy. However, on closer analysis, it is possible to identify elements of representation in its functioning, which are taken into little consideration and which could probably modify the prevalent theoretical belief. In fact, as citizens usually participate through their groups and associations, new representatives emerge challenging the traditional channels of political representation in terms of popular approval, consensus, hence legitimacy. This work aims to go beyond the prevailing narrative and propose an original interpretation of the PB’s institutional model as a new and alternative representative democracy, where the main political actors become organizations from the civil society: behind PB there seems to lie a sort of ‘civil’ democracy. Hence, introducing this alternative viewpoint can, not only further questions which are never fully considered in the literature, but also open interesting scenarios in the debate over the crisis of liberal-democratic institutions and the role and the identity of civil society.

La tesi intende analizzare l’idea coloniale in Francia durante la Terza Repubblica, le modalità attraverso cui essa veniva veicolata e gli argomenti con cui l’espansione veniva giustificata. Dopo un’introduzione storica, la ricerca si concentra sulle diverse “voci” che concorsero alla promozione e propaganda coloniale. Vengono analizzati il contributo dei diversi attori – primo fra tutti il “parti colonial” - che parteciparono a sostenere le motivazioni dell’espansione, oltre alle modalità e ai canali utilizzati, in un contesto in cui l’opinione pubblica era restia ad affezionarsi e a comprendere la necessità di un impero. La parte successiva si concentra sui contenuti del discorso di giustificazione e motivazione dell’imperialismo francese, tramite il richiamo di alcuni teorici e politici del periodo e dei principali temi -economici, politici e umanitari (la cd. “mission civilisatrice”) - evocati in tale contesto. L’ultimo capitolo è dedicato in modo particolare alla diffusione della cosiddette “scienze coloniali” e alla creazione, influenzata dall’esigenza di formare i futuri amministratori coloniali, di cattedre o sezioni coloniali negli istituti di studi superiori. E’ possibile in tal modo individuare un collegamento tra diversi gruppi ed entità operanti nel campo politico, economico e scientifico e, attraverso l’analisi degli appunti dei corsi, esaminare in che modo l’idea coloniale fosse trasmessa in tale ambito. / The research aims at analyzing the colonial idea in France during the Third Republic, the different ways it was conveyed and the main themes adopted to justify the colonial expansion. After a first historical overview, the second chapter focuses on the different actors that contributed in promoting the colonies and the colonial propaganda (above all the “parti colonial”), in a context in which the majority of the French citizens seemed not really interested in supporting the colonial empire nor in understanding its needs and methods. Subsequently, the research analyzes the different themes the supporters of the French colonial movement adopted to justify the need of a colonial empire at the economic, political and “humanitarian” levels. The last chapter is focused on the diffusion of the “colonial sciences” and the creation of ad hoc colonial sections or schools aimed at training the future colonial administrators. The analysis highlights the links between the different actors of the political, economic and scientific circles. Also, thanks to the exam of the student’s notes it is possible to see how the colonial idea was conveyed in this field.

Nell’aprile 1982, l’Argentina – un Paese alleato degli Stati Uniti attraverso il Patto di Rio – invase le isole Falkland, un Territorio d’Oltremare del Regno Unito, rivendicato da Buenos Aires sin dal XIX secolo. Margaret Thatcher, l’allora Primo Ministro britannico, rispose con vigore. Alla fine la Gran Bretagna – alleato NATO degli USA – riuscì a riconquistare le isole e a ristabilire lo status quo ante. Il conflitto va inquadrato nel framework della ‘seconda Guerra Fredda’. Il confronto tra gli Stati Uniti e l’Unione Sovietica fu particolarmente aspro nei primi anni Ottanta e la logica bipolare influenzò le dinamiche diplomatiche della guerra del 1982. Da un lato, l’Emisfero occidentale era al centro della rinnovata strategia americana anti-comunista e l’Argentina era il principale pilastro nel Cono Sud. Dall’altro lato, il rafforzamento della ‘speciale relazione’ anglo-americana costituiva la pietra angolare della grand strategy statunitense nel teatro europeo. Con questo sfondo, è naturale domandarsi quale ruolo Washington scelse di giocare nella guerra delle Falkland tra due dei suoi alleati. A causa di interessi divergenti, la ‘relazione speciale’ non fu infatti del tutto speciale. / In April 1982, Argentina – a country allied with the United States through the Rio Pact – suddenly invaded the Falkland Islands, a long-time Overseas Territory of the United Kingdom, disputed by Buenos Aires since the XIXth century. Margaret Thatcher, the then British Prime Minister, vigorously responded and finally Britain – a US NATO ally – was able to regain the Islands and re-establish the status quo ante. The conflict needs to be contextualized in the ‘second Cold War’ framework. The struggle between the United States and the Soviet Union was particularly tough in the first years of the 1980s and the bipolar logic strongly influenced the diplomatic course of the 1982 war. On the one hand, the Western hemisphere was at the core of the renewed anti-communist US strategy and Argentina was the main pillar in the Southern Cone. On the other hand, the strengthening of the Anglo-American ‘special relationship’ was the European cornerstone of the US grand strategy. Against this background, what kind of role the US chose to play in the Falklands war between two of their allies instinctively arises as the main question. Affected by diverging interests, the ‘special relationship’ was not indeed entirely special.

Questa tesi è costruita sulle seguenti domande: una società che ha vissuto gravi e sistematiche violazioni dei diritti umani come può 'chiudere i conti' con il passato e perseguire giustizia e riconciliazione? Come rigenerare i legami sociali infranti? Quale ruolo giocano vittime e perpetratori? Questi problemi sono studiati, in concreto, nell’esperienza di El Salvador. Tra i profili sociologici possibili, la tesi si concentra sulla 'domanda di giustizia' delle vittime. Il primo capitolo fornisce un inquadramento storico-sociale. Il secondo ha per oggetto la giustizia di transizione; l’analisi teorica generale considera i seguenti modelli: giudiziario, amnistiale, delle commissioni verità e la "Truth and Reconciliation Commission" (TRC) sudafricana. La TRC è presentata come un’esperienza che attinge e supera le opzioni precedenti, mostrando le potenzialità della "restorative justice". Il terzo e il quarto capitolo tornano sul caso salvadoregno e considerano gli attori (nazionali e internazionali) e i problemi sociali della transizione del Paese centroamericano. La ricerca svolta sul campo ha permesso di mettere in luce il valore generativo degli sforzi con cui parte della società civile salvadoregna ha cercato di fronteggiare la latitanza dello Stato rispetto al diritto alla verità e alla giustizia. Il quinto capitolo, avvalendosi della voce delle vittime intervistate con il metodo delle 'storie di vita', riflette sul rapporto fra trauma e legame sociale. L’ultimo capitolo presenta gli strumenti metodologici utilizzati per la ricerca empirica. / This thesis is based on the following questions: can a society that has experienced severe and systematic human rights violations be reconciled with the past and pursue justice and reconciliation? How can broken social connections be repaired? What are the roles of victims and oppressors? These problems have been studied analyzing the experience of El Salvador. Among the possible sociological profiles, the thesis focuses on the Salvadorian victims' "demand for justice". The first chapter gives an historical-social overview. The second chapter analyzes the transitional justice. The general theoretical analysis takes into account the following models: judiciary, that related to amnesty, the model of the "truth commissions", and finally the South African "Truth and Reconciliation Commission" (TRC). The TRC is presented as an experience that draws on and surpasses the previous alternatives, showing the potential of restorative justice. The third and fourth chapters return to the Salvadorean case and take into account the agents (national and international) and the social problems connected to the transition El Salvador has undergone. Research in this field sheds light on the relevance of the efforts made by some parts of the Salvadorean civil society to deal with the absence of the government with respect to promoting the right of truth and justice. The fifth chapter, corroborated by interviews with victims analysed using the method of the "history of life", reflects on the connection between trauma and social bonds. The last chapter presents the methodological tools used during the empirical research.

La tesi analizza le cause profonde dell’attuale crisi russo-ucraina esplosa nel 2014 con i moti anti-governativi di Euromajdan ed alla conseguente crisi internazionale che ha direttamente coinvolto la Federazione Russa, ed indirettamente la comunità internazionale. Analogamente, la struttura della ricerca ha prodotto altresì una ricostruzione, nei secoli, del ruolo geopolitico della stessa Ucraina nelle più ampie dinamiche interstatali dell’Europa centro-orientale. Lo studio in questione esplora nella loro profondità - e lungo oltre quattrocento pagine - gli aspetti più profondi di questa crisi nelle sue diverse, articolate e interconnesse dimensioni. L’approccio impiegato prende le mosse dalla matrice d’analisi tipica del Renouvin e delle sue forces profondes, ampliando perciò l’indagine sul piano storico, geopolitico, diplomatico, economico, giuridico, culturale e religioso. Sostenuta da una cospicua bibliografia e da un notevole apparato di note, la presente tesi non si è tuttavia limitata ad una ricostruzione delle dinamiche contemporanee del XX e del XIX secolo. L’autore ha infatti voluto procedere - nell’obbiettivo di costruire uno studio di riferimento sulla geopolitica dell’Ucraina nel sistema internazionale - dall’antichità di Erodoto e dal crollo dell’Impero Romano, per poi proseguire lungo le più importanti fasi della nascita della Rus’ di Kiev, giungendo sino ad Euromajdan. / The thesis analyzes the root causes of the current Ukrainian crisis triggered by the Euromajdan revolts of 2014 and the consequent international crisis directly involving the Russian Federation, and indirectly the whole international community. The thesis also reconstructs the secular geopolitical role of Ukraine in the broader dynamics of interstate relations of Central and Eastern Europe. The present research is an in-depth, four hundred page exploration of the many aspects of this crisis with all the complexities of its intertwined dimensions. The research employed inputs from the classical Renouvin’s forces profondes imprint; thus exploring and accounting for historical, geopolitical, diplomatic, economic, juridical, cultural and religious aspects. With the aim to produce a reference study of the historiography of Ukraine and its relationship with Moscow and the wider regional context, aided by a sound bibliography and a valuable source of notes, the author decided to begin from the ancient times of Herodotus and the collapse of the Roman Empire and work his way forward through the genesis of the Kievan Rus', up to the most recent XXI century’s geopolitics.

Il progetto si è proposto di dimostrare l’evoluzione della valenza strategica nella relazione bilaterale tra Stati Uniti ed Egitto durante le presidenze di Anwar al-Sadat e Hosni Mubarak. Sebbene si sia a lungo contraddistinta per un marcato rapporto di reciprocità e di stabilità locale e trans-regionale, da alcuni decenni a questa parte la relazione vive un particolare momento di riconsiderazione a causa della compresenza di più fattori che ne hanno limitato il valore complessivo, necessitando quindi di nuovi fondamenti e obiettivi per essere rivitalizzata. Riprova di ciò sono proprio gli accordi di Camp David, cuore pulsante delle strategie comuni di Stati Uniti ed Egitto, nonché centro nevralgico delle dinamiche di cooperazione, per lo più di sicurezza, tra statunitensi, egiziani e israeliani. Analizzando gli elementi caratterizzanti la politica estera egiziana in relazione, anche e non soltanto, alle interazioni con Stati Uniti e Israele, prendendo come riferimento una prospettiva storico-diacronica che tenesse conto delle evoluzioni politiche dentro e fuori il Paese arabo, all’interno di un più ampio panorama geopolitico e strategico regionale e internazionale, il presente lavoro ha pertanto puntato a far emergere il carattere tattico del rapporto stesso, il quale è stato fortemente influenzato dal perseguimento di un interesse nazionale da entrambe le parti. / The thesis analyses the evolution and impact of U.S.-Egypt relations under the Sadat and Mubarak’s tenure in terms of geopolitical and strategic attitudes through a historical-diachronic perspective. Although it has been characterized for decades by a marked reciprocity in terms of local and (trans-)regional dynamics, for about twenty years this link has been experiencing a particular moment of reconsideration due to the presence of several factors that have limited its overall significance. The bilateral relationship needs new foundations and objectives. In fact, the thesis argues that the Camp David agreements, the beating heart of the common strategies of the United States and Egypt, as well as the political core of several dynamics (mostly in security dimension) between the Americans, Egyptians and Israelis, it is the key element to understand the interconnection between Egyptian domestic state and its regional state autonomy. In this respect, the thesis highlights these factors characterizing the Egyptian foreign policy in connection, even and not only, with United States and Israel, as enabling factors both in the national political developments and the evolution in the Arab stage, within a wider geo-political and strategic regional and international panorama. In conclusion, this work aim to bring out the tactical nature of the bilateral relationship between Egypt and the United States, which was heavily influenced by the pursuit of a different perception of national interest. Therefore, the biggest challenge between Washington and Cairo consists in managing a much less special and complex relationship than in the recent past, which essentially sees the overcoming of Camp David, while maintaining the stability of the region as a cornerstone on both sides.

The Sultanate of Oman is often described by the international media as a peaceful exception in the turbulent Middle East. Most authors studying Oman’s history and politics agree that discretion, consultation, peaceful neighborhood relations and independence from the greater powers operating in the region have been the constant elements of the country’s contemporary foreign policy. Moreover, it is widely argued that Oman’s foreign policy approach derives from the country’s national identity, including its Ibadi tradition and the cosmopolitan character of the Omani maritime history. Despite the extensive use of terms like a “non-aligned” or “neutral” foreign policy deriving from a “tolerant” or “peaceful” identity, both by academics and journalists to describe the country’s behavior, a careful reflection on the appropriate application of these concepts to the Omani case is still missing. The aim of my research is to deconstruct essentialist understandings of Oman's identity and foreign policy, by looking at how discursive alignments and identity contents varied to support the government's quests for legitimacy, recognition, and status. By adopting a Discourse Historical Approach (DHA), the work compares the National Day speeches and the UN GA speeches under the entire reign of Sultan Qaboos bin Said Al Bu Saidi (1970 – 2020), to look at how discourse changed based on the time, issue, and audience of reference. More broadly, this research seeks to provide an underexplored perspective on Oman’s foreign policy, at the same time contributing both to the theoretical debate on small states’ alignments and to the discussion on the Gulf Cooperation Council (GCC) states’ foreign policies and identities.

In an attempt to make concrete linkages between neighborhood change and the boundary-making paradigm, this field and historical study of a New York City's neighborhood, addresses the influences of displacement, housing- abandonment and resettlement in Super-gentrification processes on 1) the types of institutions that emerged to represent different class interests; 2) the types of social groups that came to inhabit the neighborhood; 3) the pattern of that evolution over time; 4) the particular goals, values, and morals that such community organizations evolved; and 5) the social status displays carried out in cultured consumption in housing and leisure. Employing a multi-methodological and theoretical approach, the study follows the evolution and development of neighborhood change over forty years through the analysis of social groups and their community organizations (looking at archival documents for the past and by in-depth interviews, shadowing and ethnographic observation for the present time), census data analysis, archival/documental research, and visual data. Community organizations emerged, on the one hand, to represent different class interests - improvement, mandated, ideological - and to emphasize liberal progressive values, on the other. This emergence followed historical and geographical patterns of accelerating gentrification. The study argues that four waves of gentrification showed up across the time and tended to concentrate in four different neighborhood areas, where the incoming groups formed parallel boundary shifts. Accordingly, I found that different waves of gentrification were associated with the emergence of different types of Gentrifiers over time, and this had to do with the changing role of post-industrial cities within the American economy, the processes of government/local institution interventions in the neighborhood housing market, the changes in class interests, morals and ideologies, and the increased aestheticized re-scriptings of neighborhood housing choices and lifestyles. Such aesthetic appreciation operated for gentrifiers as a visible marker of social status. As residential displacement, the disappearance of "old" local stores, and their replacement of upscale shops entailed forms of social inequality that enhanced the lifestyle of new waves of gentrifiers (raising housing values and rents) while, at the same time, forced out morally (by alienation) or practically (by displacement) long-term residents, who helped produce the neighborhood socio-cultural fabric. Diversity and aesthetic appeal seemed to underlie the motives of wealthier, well-educated newcomers to move into the neighborhood. Interestingly, those have not been changing throughout the different waves of gentrifiers who came to inhabit the community in the last 40 years. However - during the process of Super-gentrification - I found that the more they populate the neighborhood, the more it becomes homogenized and less richly diverse, still quite progressive but in a different way. I would say, in a privileged progressive way. Despite the fact that the moral order of these institutions has always been the one of community solidarity, culture, education, and growth, I observed at the same time the playing out of the most common paradox of gentrifiers. The desire of diversity and the producing of difference. This is, I believe, the central problem of gentrification: the balance between, or the combination of, pleasure and power. Balancing pleasure and power is a social, political, and moral problem. It brings together many of the concerns about gentrification, the desire for (and the loss of) diversity, and expresses the central thesis of this study.